Boeing and Alaska Airlines on Monday announced an order for five additional Next-Generation 737-900ERs (Extended Range). The order, valued at $481 million at list prices, continues Alaska Airlines’ investment in its fleet and efforts to improve fuel performance.

“Today’s announcement supports our goal of growing Alaska Airlines by 4 to 8 percent a year,” Mark Eliasen, Alaska Air Group’s vice president of finance and treasurer, said in a press release. “The 737-900ER is a great aircraft, with the cost efficiency and reliability needed for us to be successful in today’s competitive marketplace.”

“The order of five additional 737-900ERs is an affirmation of our hometown partner’s successful strategy of offering customers good value, delivering a great onboard experience and running an on-time airline,” said Brad McMullen, vice president of North America Sales, Boeing Commercial Airplanes.

“The 737-900ER offers Alaska Airlines the best seat-mile cost of any single-aisle airplane in production, which is especially important with today’s high fuel prices. The interior also complements Alaska’s excellent customer service, providing the passengers with a wonderful flying experience,” he continued.

The largest and newest model in the Next-Generation 737 family, the 737-900ER can carry up to 26 more passengers or fly about 500 nautical miles (926 km) farther than the 737-900. Alaska Airlines operates the 737-900ER in a two-class configuration with 181 seats and features the Boeing Sky Interior.

The Boeing Sky Interior is the latest in a series of enhancements for both airlines and passengers that introduces new lighting and a curving architecture that create a distinctive entry way. Passengers enjoy a more open cabin feel and an environment simulated by light-emitting diode (LED) lighting. The interior also features sculpted sidewalls and newly improved and expanded pivot bins.

In addition, all of Alaska’s seats will feature outlets providing dual 110-volt and USB power.

The longer range of the 737-900ER can connect distant city pairs across continents, such as Seattle to Orlando, Fla., in a generous two-class configuration. It has substantial economic advantages over competing models, including 6 percent lower operating costs per trip and 4 percent lower operating costs per seat mile.

With today’s order, Alaska Airlines now has unfilled orders for 35 737-900ERs and 37 737 MAX airplanes.